System and method for thermally manipulating a combination of a top and bottom substrate before a curing operation

ABSTRACT

A system and method cures a combination of a top and a bottom substrate with a resin disposed in-between. A cure device inherently warps the combination in one direction as a result of a curing operation that the cure device performs on the combination. A temperature gradient inducing device is disposed closer to one of the top and bottom substrates to create a temperature gradient between the top and bottom substrate and thereby warp the combination in a direction opposite to the one direction.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority, under 35 U.S.C. § 119(e), toprovisional application Ser. No.60/065,579, filed Nov. 12,1997, which ishereby incorporated by reference in its entirety.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to the following applications, all of whichare filed on the same date that this application is filed, all of whichare assigned to the assignee of this application, and all of which areincorporated by reference in their entirety:

System and Method for Maintaining Concentricity of a Combination of aTop and Bottom Substrate During the Assembly of a Bonded Storage DiskU.S. patent application Ser. No. 09/081,115.

System and Method for Curing a Resin Disposed Between a Top and BottomSubstrate with Thermal Management U.S. patent application Ser. No.09/081,154.

System and Method for Forming Bonded Storage Disks with Low Power LightAssembly U.S. patent application Ser. No. 09/081,536.

System and Method for Dispensing a Resin Between Substrates of a BondedStorage Disk U.S. patent application Ser. No. 09/081,116.

System and Method for Distributing a Resin Disposed Between a Top andBottom Substrate U.S. patent application Ser. No. 09/081,537 and

Improved System and Method for Curing a Resin in a Bonded Storage DiskU.S. patent application Ser. No. 09/081,117.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to bonded storage disks and, more particularly,to improved methods of and systems for forming bonded storage disk, suchas digital versatile disks ("DVDs").

2. Discussion of Related Art

Two popular forms of storage media are compact disks ("CDs") and digitalversatile disks ("DVDs"). Each is a form of a bonded storage disk. Abonded storage disk has two or more substrates held together by a curedbonding agent. At least one of the substrates is formed to have "pits,"the distribution of which is representative of the information to bestored on the disk. These pits are metallized so that when they are"hit" by an optical signal they will reflect a signal indicative of thepit and thus the information.

Because of their ability to store vast amounts of information, DVDs havebeen well received in the market. To date, there are four specified DVDformats: DVD5, DVD9, DVD10, and DVD18. DVD5 is a single-sided,single-layered format (see FIG. 1C); DVD9 is a single-sided, duallayered form (see FIG. 1E); DVD10 is a dual-sided, single-layered format(see FIG. 1D); and DVD18 is a dual-sided, dual-layered format (see FIG.1F). "Single-sided" means that the disk is intended to be read from oneside only. "Dual-sided" means that the disk may be read from eitherside, with each side storing information. "Single-layered" means thatfor a given side there is one "layer" of information only. In thisregard, a layer of information would mean a distribution of metallizedpits 4, which when hit with a light source 9 will reflect aninformation-carrying optical signal. "Dual-layered" means that for agiven side there are two layers 4 of information. The specifications areprovided in the DVD Book, v. 1.0, by the DVD Forum, which is herebyincorporated by reference in its entirety. The Figures are not to scale.For example, in actuality the substrate 6 is about 0.6 mm thick; forDVD9 the bonding layer 8 is about 50 microns thick ±15 microns, ±10microns within a DVD, and ±4 microns within a revolution; and themetallization layer 4 is on the order of tens of nanometers.)

The formats specify several, but not all, characteristics of a disk. Forexample, referring to FIGS. 1A-F, which show a plan view of a DVD and across-section view of DVD5, DVD9, DVD10, and DVD18 formats, the formatsspecify the inner diameter of the center hole, the outer diameter of theDVD, the handling area, the inner mirror band, the data area, and theouter mirror band. They also specify the shape and location of astacking ring, the pit size, the reflectivity of the metal layers andthe type of the metal, and for some formats the thickness and opticalcharacteristics of the bonding agent used to form bond layer 8. Inaddition, the specifications list acceptable tolerances of certain "bulkparameters," such as "radial tilt" and "tangential tilt." Thespecifications also specify the thickness of the bonding layer and theacceptable amounts of bubbles and contaminants.

On the other hand, some aspects are undefined. For example,commercially-available substrate molding machines produce substrateshaving machine-specific moat locations and shapes. In the art, forexample, there are known 22 mm moat geometries and 34 mm moatgeometries. In addition, though the reflectivity of the metal layers isspecified (sometimes by minimums, other times by minimums and maximums)the actual amount of metallization is not.

Typical DVD players include an optical reading mechanism fortransmitting an optical signal to a surface of the DVD and for reading areflected signal. Typically, this mechanism will read a bottom surfaceof the DVD, as perceived by an end-user and a DVD player. For two-sidedformats, the DVD needs to be flipped to read the other side of the DVD.For dual-layer formats, the player adjusts the focus of the opticalsignal to read a given layer of the two layers of a given side. Oneorientation is used to illuminate a semi-reflective layer (which wouldbe nearest to the read mechanism) and another orientation is used toilluminate a reflective layer (which would be farthest from the readmechanism). When reading the reflective layer, the optical signal passesthrough the semi-reflective layer and the bond layer on its way to andfrom the reflective layer, thus making the bond layer an opticalcomponent.

To date, manufacturing DVDs has been problematic, especially fordual-layer formats and especially for achieving desirable yields. Inpart this is the result of the extremely tight manufacturing tolerancesspecified by the formats and required by the market. In other part thisis due to the complexities introduced with the dual-layer arrangementshaving the bonding layer be an optical component of a DVD.

Known systems are operating at undesirably low yields. Moreover, due tothe difficulty in manufacturing these disks, many if not all DVDmanufacturing systems operate as batch processes. These are undesirablebecause they require partially completed disks to be stored and stagedbefore a subsequent manufacturing step is performed, thus increasing thecost and complexity of manufacturing.

Consequently, there is a need in the art for a system and method thatcan manufacture DVDs, including dual-layered disks, at high yields.There is also a need in the art for an in-line system that canmanufacture DVDs, including dual-layer format DVDs, at acceptableyields.

SUMMARY

Under a preferred embodiment, a system and method cures a combination ofa top and a bottom substrate with a resin disposed in-between. A curedevice inherently warps the combination in one direction as a result ofa curing operation that the cure device performs on the combination. Atemperature gradient inducing device is disposed closer to one of thetop and bottom substrates to create a temperature gradient between thetop and bottom substrate and thereby warp the combination in a directionopposite to the one direction.

BRIEF DESCRIPTION OF THE DRAWING

In the drawings,

FIGS. 1A-F show the geometries of DVDs according to known DVD formats;

FIG. 2 is a plan view of an exemplary system;

FIGS. 3A-3E show an exemplary conveyor;

FIGS. 4A-I show an exemplary metallization station;

FIGS. 5A-B show an exemplary dispense station;

FIG. 6 shows an exemplary substrate flipper;

FIGS. 7A-E show an exemplary dispense robot;

FIGS. 8A-B shows an exemplary plate of a top station;

FIGS. 9A-K show an exemplary bottom station;

FIGS. 10A-B show an exemplary rotary union;

FIGS. 11A-D show an exemplary top substrate bowing device;

FIGS. 12A-C show an exemplary dispense machine;

FIGS. 13A-B show an exemplary spin station robot;

FIGS. 14A-E show an exemplary spin assembly;

FIGS. 15A-H show an exemplary cure table assembly;

FIGS. 16A-D show an exemplary pre-cooling device;

FIGS. 17A-D show an exemplary lamp assembly; and

FIGS. 18 show an exemplary post-cooling device.

DETAILED DESCRIPTION

Preferred embodiments of the invention provide an in-line manufacturingsystem that attains high yields for bonded storage disks even fordual-layer formats. The system and method include novel resindispensing, resin spinning, resin curing, and thermal management of thedisks and the system. They also include novel aspects in the handling ofsubstrates.

In this description, unless otherwise noted, reference to a top or abottom substrate refers to a manufacturing perspective in which a topsubstrate is positioned above a bottom substrate during assembly of aDVD. This reference is the same as that of a DVD player's perspectiveexcept for DVD9 format in which case the top substrate from themanufacturing perspective will be the bottom substrate from the DVDplayer's perspective.

1. Overall System

FIG. 2 is a plan view of an in-line manufacturing system 5 according toa preferred embodiment of the invention, shown working in conjunctionwith commercially-available molding machines 10, 15 and in-feed handlingsystem 20. The preferred system is capable of making, under programmaticcontrol, DVDs according to the DVD5, DVD9, and DVD10 formats.

Each exemplary mold station provides 0.6 mm disk substrates 6. Onemachine produces a top substrate for an eventual DVD and the otherproduces a bottom substrate. Each substrate has a distribution of "pits"representative of the information stored by the eventually-formed DVD.As explained above, the top substrate for DVD5 has no information layer.

The substrates 6 are received by in-feed station 20, which may performsome initial handling and processing steps (e.g., ionization), and whichtransfers the substrates on to conveyor 25.

The conveyor 25 carries the substrates 6 in a sequence of neighboringtop and bottom substrates to metallizer station 30, which forms areflective or semi-reflective metallization layer on one side of asubstrate 6 and which transfers metallized substrates back on to theconveyor 25. All substrates 6 are metallized except for DVD5 format inwhich case every bottom substrate is metallized.

The conveyor 25 then carries the substrates 6 with the metallizationface-up to dispense station 35. The dispense station 35 includesmechanisms for arranging two consecutive substrates 6 (i.e., a top andbottom substrate) into alignment, with metallized surfaces facing eachother in a bowed relationship to receive a UV-curable bonding agent("resin") in fluid state between the two aligned substrates. Themechanisms form a ring-like capillary bridge of resin between the topand bottom substrates. A resulting combination 7 of substrates andbonding agent ("combination") is transferred back to conveyor 25.

The conveyor 25 then carries the combination 7 to spin station 40. Thisportion of conveyor 25 will be populated with combinations 7 at everyother conveyor index. The spin station 40 and dispense station 35 areseparated to allow capillary forces sufficient time to cause a desirabledistribution of the resin extending to, but not beyond, the moats of thesubstrates. The spin station 40 spins the combination to distribute theresin more evenly and to better fill the space between the twosubstrates.

The spun combination 7 is then transferred to cure station 45. Curestation 45 subjects the combination to a thermally-managed UV cureprocess to cure the bonding agent and bond together the two substratesof a combination 7 to form a DVD.

The DVD is then transferred to finishing station 50, which performsquality assurance testing and transfers the cured DVD to an appropriaterack of acceptable DVDs or rejected DVDs.

The various stations are managed, monitored, and controlled by controlstation 55. As will be explained below in context, control consists ofthe proper sequencing of a variety of pneumatical and electricalactuation in conjunction with the proper sequencing of vacuum andactivation of valves and pumps. To keep the figures uncluttered,plumbing lines for resin, vacuum, and electrical signals are omitted, asare other conventional mechanisms such as pumps, tanks, and the like.

The discussion below is often described in relation to advancing asubstrate 6 or combination 7 by "index" position. In this regard, unlessotherwise noted, one index position corresponds to a unit of time. Thisunit of time in turn will depend on the type of DVD being manufactured,as will be explained below. Thus, distances measured in index positionscorrelate to time. Because the control of the system is effectivelyevent driven, the index time may fluctuate and may involve some jitter.

The various stations and conveyor are enclosed and include air-cleaningmechanisms to attain a class 100 clean-room rating. Unless otherwisenoted references to vacuum means about 22 inches of water.

2. Molding Stations

The system 5 is designed to work with automated injection moldingstations 10, 15 to provide molded substrates 6. Exemplary moldingstations include the Discjet 600 from Netstal and the SD30 fromSumitomo. Though the DVD specification calls for a finished innerdiameter of 15 mm, the system 5 preferably operates with substrateshaving inner diameters of between 15.04 mm and 15.08 mm to facilitatethe handling of substrates.

3. In-feed Station

An exemplary in-feed station 20 is the FLT U3000 available from FirstLight Technology, Inc., with software control to ensure that top-bottompairs of substrates are presented to the conveyor 25. Conveyor index 21receives a top substrate and index 22 receives a bottom substrate forDVD5 and DVD10 formats (stacking ring, if any, projecting down); for DVD9 this top-bottom positioning is reversed. Both substrates are placedstacking ring down, moat side up.

4. Conveyor

Referring to FIG. 2, under a preferred embodiment, there are 14 indexpositions between in-feed station 20 (index position 22) andmetallization station 30 thus corresponding to a time delay ofapproximately 32 seconds. During this time, the cooling fans areactivated to cool the substrates 6 from approximately 250° F. toapproximately 80° F. There are 10 index positions between the dispensestation 35 (index position 37) and the spin station 40 thuscorresponding to a time delay of approximately 23 seconds. Each index isseparated from a neighboring index by about 3 inches.

The structure of the conveyor 25 is shown better in FIGS. 3A-E. Conveyor25 includes a drivable, programmatically-controllable track 300 having"index" positions defined by spring-loaded, substrate-centering conveyorarbors 302 that project upward through a center of a conveyor nest 304on which substrates or combinations may rest. The conveyor usesconventional driving and cooling technology and enclosures, such as thatused in the U3000 family of systems from First Light, Inc., but hasimproved arbors 302 and nests 304. The conveyor 25 includes a stand (notshown) to align conveyor nests 304 with the various stations to whichand from which substrates 6 or combinations 7 are transferred, asdescribed below.

Conveyor nest 304 is shown more particularly in FIGS. 3B-C, inperspective and cross-section views. The nest 304 is preferably made ofultra high molecular weight ("UHMW") plastic but could be made of anyother material that is suitably smooth and that has a similar wearcharacter. FIG. 3C particularly shows the production dimensions of apreferred nest 304. The sizes of the dimensions measured in inches areshown in Table 1, below.

                  TABLE 1                                                         ______________________________________                                               dimension     size                                                     ______________________________________                                               A             1.69                                                            B             1.25                                                            C             1.02                                                            D             0.868                                                           E             0.808                                                           F             0.04 × 45°                                         G             0.125                                                           H             0.063                                                           I             0.062                                                           J             0.792                                                           K             0.03                                                            L             0.149                                                           M             30°                                                      N             0.640                                                           O             0.734                                                           P             0.886                                                           Q             1.002                                                           R             1.25                                                            S             1.75                                                            T             2.00                                                            U             45°                                                      V             0.04 × 45°                                         W             1.062                                                           X             1.023                                                           Y             0.309                                                           Z             0.637                                                           AA            15°                                                      BB            45°                                                      CC            .010 RAD.                                                       DD            15°                                               ______________________________________                                    

Though some aspects of nest 304 are the result of legacy issuesconcerning the conventional driving mechanisms, other aspects of theshape are novel. An upper surface 306 has an outside diameter wideenough to support the handling area of a substrate 6 and has a hole 308through which a conveyor arbor 302 (see FIGS. 3D-E) is positioned. Morespecifically, the internal bore of the hole 308 has a diameter, length,and beveled shape 309 chosen to mate with a preferred conveyor arbor302, so that the arbor 302 may be biased upwardly through the hole, butstopped by bevel 309 so that arbor 302 centers itself. The hole 308 alsoallows the arbor 302 to be depressed downward through the hole 308 belowthe surface 306. This allowable movement in conjunction with thespring-loaded nature and shape of the arbor 302 forms part of aconcentricity constraint for eventually formed combinations 7. The otherpart of the concentricity constraint is formed by pick heads of handlingrobots, discussed below.

Conveyor arbor 302 is shown more particularly in FIGS. 3E-G, inperspective, cross-section, and plan views. The arbor 302 is preferablymade of hardened and polished tool steel that is electro-less nickelplated. FIG. 3E particularly shows the production dimensions of apreferred arbor 302. The sizes of the dimensions measured in inches areshown in Table 2, below.

                  TABLE 2                                                         ______________________________________                                               dimension     size                                                     ______________________________________                                               EE            0.730                                                           FF            0.587                                                           GG            0.474                                                           HH            0.150 RAD.                                                      II            0.060                                                           JJ            0.22                                                            KK            0.302                                                           LL            0.419                                                           MM            0.03 × 45°                                         NN            0.40                                                            OO            0.806                                                           PP            30°                                                      QQ            0.004 RAD.                                               ______________________________________                                    

The arbor 302 is shaped to fit into upper portion 307 of nest 304, yetbe constrained from entirely passing through the hole 308. Angledportion 316 mates with beveled portion 309 of nest 304, so that thearbor may center itself when projecting upward. The arbor 302 is alsoshaped to allow its downward movement through the bore of hole 308.Arbor 302 includes an inner recess 314 to receive a stainless steelbiasing spring (not shown) to allow the arbor 302 to move vertically inresponse to the application and removal of force. The other end of thespring rests against a plate (not shown) carried by conveyor 25. Apreferred spring has a diameter of 0.375 inches, a length of 1.75 inchesand a wire diameter of 0.035 inches. When upwardly biased by the spring,the arbor 302 projects above the upper surface 306 of the conveyor nest304 by about 0.25 inches. In response to the application of downwardforce, the arbor can be pushed below surface 306 of nest 304. Thisallowable movement forms part of a concentricity constraint foreventually formed combinations 7. A rounded edge 310 of an upwardlyprojecting portion 312 of the arbor facilitates the handling of thesubstrates to transfer them on or off the arbor 302. This is so becausethe handling robot only needs to center the i.d. hole of a substrate onthe approximately 0.47 inch diameter of the upper portion of the arbor302, and gravity in conjunction with the low friction surface will causethe substrate to nest around the approximately 0.587 diameter of a lowerportion of the upwardly projecting portion 312. Hole 318 is used toreceive mounting hardware (not shown).

5. Metallization Station

A preferred metallization station 30 (see FIG. 2) includes a dualcathode sputtering device 402 (see FIG. 4A) and a two-arm metallizerrobot 400 (see FIGS. 4B-I). The sputtering device 402 and robot 400 aremounted on stands (not shown) to place them in alignment with theconveyor 25 (see FIG. 2), as described below.

The metallization station 30 is responsible for receiving substrates 6pit-side up and producing metallized substrates with metallization faceup. The metallization covers the pits within a predetermined range ofreflectivity to produce an information layer.

a. Operation

In operation, pick heads 406 and 408 are actuated downward tosimultaneously vacuum-grab a metallized substrate from opening 404 and asubstrate 6 from conveyor 25 at index position 31 (see FIG. 2). Duringthe same index interval that the substrates are grabbed, i.e., withoutadvancement of the conveyor 25, the pick heads are actuated upward tolift the grabbed substrates, rotate 180° about axis 410, and lower andrelease a substrate 6 to device opening 404 and a metallized substrateto the conveyor 25 at index 31.

The substrate grabbed from index 6 is subsequently sputtered by thesputtering device 402, under programmatic control, to metallize a topsurface of a received substrate with one of either a reflective orsemi-reflective metal. The substrate grabbed from device 402 andreleased on the conveyor 25 is carried to dispense station 35.

For DVD5 format, every bottom substrate on the conveyor 25 is sputteredwith aluminum and every top substrates is unsputtered. Under a preferredembodiment, the top substrates are not grabbed by the metallizer robotand instead immediately advance to the dispense station. This causes acertain off-set between the pairs of substrates that were initiallypresented to the conveyor 25, but the sequence of top-bottom substratesis maintained. In another embodiment, the top substrate is presented tothe sputtering device but is not metallized. For DVD9 format, every topsubstrate is sputtered with aluminum, for example, and every bottomsubstrate is sputtered with gold, for example. For DVD10 format, everysubstrate is sputtered with aluminum.

b. Sputtering Device

A preferred dual-cathode sputtering device 402 is described in U.S. Pat.No. 5,709,785, which is hereby incorporated by reference in itsentirety. For the sake of brevity that description is not repeated here.The sputtering device 402 is capable of receiving a substrate 6 onceevery index interval and providing a metallized substrate once everyindex interval. There is a four index interval delay between the timewhen a substrate 6 is presented to the sputtering device 402 and when itemerges. The sputtering device 402 may be controlled to sputter a givensubstrate with one of the two cathode metals, e.g., aluminum or gold. Inthis fashion, the substrates may be sputtered with a reflective orsemi-reflective material to form one of the information layers specifiedin a DVD format.

Under a preferred embodiment, the sputtering device is controlled toprovide between 60-70% reflectivity for the reflective surface for DVD5;about 24% reflectivity for the semi-reflective surface and 60-70%reflectivity for the reflective surface for DVD9; and for about 60-70%reflectivity for DVD10. Like other process parameters the amount ofreflectivity may be adjusted by the user. Moreover it has beendiscovered by the inventors that the distribution of metal layer 4 isnot even; the sides of the pits have substantially less metal than thetops.

c. Metallizer Robot

Under a preferred embodiment, the metallizer robot 400 rotates 180°about axis 410 under programmatic control of rotary servo 412. The pickheads 406 and 408 are mounted to pistons 405 which are programmaticallycontrolled to move downward and upward. Each pick head 406 and 408includes a load-lock assembly 414 to mate with an opening 404 of thesputtering device 402 to create a suitable vacuum seal.

More specifically, the servo 412 (part no. CP DR-5030B available fromCompumotor) is mounted on a plate 416 which holds end stops 418 toprevent over-rotation and limit switches 420 to further facilitate inthe prevention of over-rotation. Plate 416 is mounted to adapter 422which is used to mount the robot 400 on a stand (not shown). Sheath 422is used to hold plumbing (not shown).

An upper portion 413 of robot 400 is mounted to servo 412 with mountinghardware 411 and includes a cap 423 and equal length and radial arms 424and 425 to which are mounted pneumatically-controllable pistons 405.Aluminum load-lock assemblies 414 mount to pistons 405 (part no.CDQ2KWB32-UIA970655 available from SMC) and include a gasket 415 (partno. 2-356B70 available from National) mounted in recess 434 on thepolished underside of lip 432 to help seal the assembly 414 withsputtering device opening 404 when so positioned. With particularreference to FIGS. 4E-G, an inner diameter ring 426 ("i.d. ring") iscompression fit into annular chamber 436 on the underside of load-lockassembly 414 and is in fluid communication with vacuum port 429 by a0.113 inch diameter gland 438 in housing portion 428. A preferredembodiment uses an i.d. ring 426 available from First Light, Inc. aspart no. 10108. By application of vacuum to port 429 the ring 426 may becaused to vacuum grab a substrate 6 within a handling region of thesubstrate 6. Vacuum port 430 is used to create a vacuum within opening404 of the sputtering device, before a substrate is presented into aninner chamber (not shown) of device 400.

FIGS. 4E-G particularly show the production dimensions of a preferredload lock assembly 414. The sizes of the dimensions measured in inchesare shown in Table 3, below.

                  TABLE 3                                                         ______________________________________                                               dimension     size                                                     ______________________________________                                               A             6.00                                                            B             4.75                                                            C             3.38                                                            D             1.25                                                            E             0.906                                                           F             0.453                                                           G             0.6305                                                          H             0.199                                                           I             .005/.010                                                       J             .06 × 45°                                          K             45°                                                      L             0.188                                                           M             0.250                                                           N             0.385                                                           O             0.766                                                           P             2.134                                                           Q             0.28                                                            R             0.085                                                           S             0.2                                                             T             0.25                                                            U             0.721                                                           V             .005 RAD.                                                       W             0.173                                                           X             0.055                                                           Y             0.625                                                           Z             0.665                                                           AA            0.366                                                           BB            0.625                                                           CC            0.689                                                           DD            0.753                                                           EE            0.82                                                            FF            0.94                                                            GG            0.998                                                           HH            5.35                                                            II            0.13                                                            JJ            0.72                                                            KK            1.036                                                           LL            0.269                                                           MM            .03125 RAD                                                      NN            0.015 RAD.                                                      OO            24°                                                      PP            0.173                                                           QQ            0.18                                                            RR            0.17                                                            SS            0.75                                                            TT            0.438                                                           UU            0.12                                                            VV            0.19                                                     ______________________________________                                    

The structure of i.d. ring 426 is shown in FIGS. 4H-I in perspective andcross-section views. Ring 426 preferably has a durometer rating of 55.The ring 426 is defined by angled lip 446, projecting up and radiallyoutward, and angled lip 448, projecting up and radially inward. Anannular region 450 is defined in-between and at a base of the lips.Twelve equally-distributed holes 442 of about 0.06 inch diameter extendthrough region 450. FIG. 4I particularly shows the production dimensionof a preferred ring 426, and table 4 shows the sizes of these dimensionsmeasured in inches.

                  TABLE 4                                                         ______________________________________                                                dimension      size                                                   ______________________________________                                                WW             1.065                                                          XX             1.025                                                          YY             0.939                                                          ZZ             0.811                                                          AAA            0.725                                                          BBB            0.685                                                          CCC            0.177                                                          DDD            0.115                                                          EEE            0.75                                                           FFF            1.0                                                            GGG            0.049                                                  ______________________________________                                    

6. Dispense Station

A portion of a preferred dispense station 35 is shown in plan view inFIG. 5A. Dispense station 35 includes a dispense robot 502, and twodispense machines 504 and 506, each having a top station 510, a bottomstation 508, a resin dispenser 514, and a top substrate bow device 512(see FIG. 11A). FIG. 5B shows a dispense machine, e.g., 504, shown inside elevation view. Not shown in these Figures, but shown in plan viewin FIG. 2, is a robot substrate flipper 600 (see FIG. 6) at index 33.The dispense machines, flipper, and robot are mounted in alignment sothat substrates may be removed from conveyor 25 at indexes 36 and 37 andso that substrates may be returned to index 36, as explained below.

The dispense station 35 is responsible for receiving a top and a bottomsubstrate 6, moat-side up (and consequently metallization, if any,face-up), from conveyor 25 and producing a combination 7 of substratesin which a top substrate's and a bottom substrate's moat side face eachother and in which a bubble-free capillary bridge of resin is disposedas a ring-like pattern between the substrates. As will be explainedbelow, this distribution of resin should distribute itself furtherthroughout a region between the substrates as a consequence of capillaryforces, and the consequent distribution should extend radially inward tothe moat and should be substantially bubble-free.

a. Operation

In operation, a robot flipper 500 (see FIG. 6) of dispense station 35lifts every top substrate off a conveyor nest at index 33, rotates thesubstrate 180° so the top substrate is now moat-side down, and lowersthe substrate back on to the same conveyor nest.

While one top substrate is being flipped, two neighboring substrates 6are at index positions 36 (bottom substrate) and 37 (top substrate).

A dispense robot 502 vacuum grabs the two substrates at indexes 36 and37 and moves them to an open dispense machine, i.e., one which is notcurrently in the process of forming a combination 7. The top substrateis moved to a top station 510 (see particularly FIG. 5B) of a given,open dispense machine, e.g., 504, and the bottom substrate is moved to abottom station 508 of the open machine.

A top substrate bow device 512 (see FIG. 11A) of that machine then grabsand lifts the top substrate from the top station 510 and moves it intovertical alignment with the bottom substrate at the bottom station. Thetop substrate bow device 512 and bottom station 508, under programmaticcontrol, cause the two substrates to form a bowed relationship accordingto a preferred bow profile and to rotate while maintaining this profile.The top substrate is bowed concave up, and the bottom substrate is bowedconcave down.

A resin dispenser 514 of the dispense machine is programmaticallycontrolled to move to a preferred position relative to the bow profileand to dispense a resin in the bowed opening to form a ring-likecapillary bridge between the substrates. The substrates are thenreleased at a controlled rate from the bow device 512 and bottom station508 under programmatic control.

Prior to and while the above is occurring the other dispense machine,e.g., 506, has been in the process of doing the same to a different pairof top and bottom substrates and has finished forming a combination 7.During the same index interval that the substrates are removed fromindexes 36 and 37 and provided to one dispense machine, the robot 502moves a combination 7 from the bottom station 508 of the other machineand moves into index 36. This process is repeated to use the twodispense machines 504 and 506 in interleaved fashion.

b. Robot Flipper

The structure of robot flipper 600 at index 33 (see FIG. 2) is shown inFIG. 6 in perspective view. Flipper 600 includes two identical outerdiameter, arcuate gripping arms 614 held by rotary grip 617 so that thearms form a partial circle. Each arm includes grooved fingers 616 havinga lengthwise groove. The arms 614 and fingers 616 are shaped to grab anedge of a substrate when the arms are moved inward as shown by arrow618, and to release the edge when the arms are moved outward as shown byarrow 620. The rotary grip 617 (part no. MRHQ16S-180S-F 9PVL-F9PLavailable from SMC) has linear actuation of the arms along arrows 618and 620 and rotary actuation about axis 622 which is parallel to alongitudinal direction of each arm, as defined by arm members 624. Apneumatically-controllable actuator 626 (part no. MGQL20-100-Z73available from SMC) is mounted on stand 628 and holds rotary grip 617 sothat when the actuator is in a lowered state the grooves of fingers 616are in substantial horizontal alignment with and radially outward of atop substrate at index 33 and so that when the actuator is in a raisedstate there is substantial vertical clearance to rotate the arms 614about axis 622 180°. In this fashion, the arms 614 may be actuatedinward as shown by arrow 618 to grab a substrate at index 33, to raiseit, and to flip it, and they may be actuated outward as shown by arrow620 to release a flipped substrate back on to a conveyor nest at index33.

c. Dispense Robot

The structure of dispense robot 502 is shown in FIGS. 7A-E inperspective exploded and cross section views. Dispense robot 502includes a dual grabber assembly 730 that, under programmatic control,may be rotated about axis 731 by rotary servo 732 to place the grabberassembly in three states: a first state vertically aligns grabberassembly 730 above indexes 36 and 37 (as shown in FIG. 5A); a secondstate vertically aligns grabber assembly 730 above a top station 510 andbottom station 508 of a first dispense machine 504; and a third statevertically aligns grabber assembly 730 above a top station 510 andbottom station of a second dispense machine 506. In any of the threestates, the grabber assembly 730, under pneumatic control, may belowered as shown by arrow 733 to grab substrates from the conveyor 25,to release the substrates to a top and bottom station of one of the twodispense machines, or to grab a combination 7 from a bottom station 508of one of the two dispense machines. Likewise, the assembly 730 may beraised to lift substrates from the conveyor 25, to rotate the assembly730 out of position after the release of the substrates to a top andbottom station of one of the two dispense machines, or to lift a grabbedcombination 7 from one of the two dispense machines.

The servo 732 (part no. CP DR-5030B available from Compumotor) ismounted to plate 738 through a collar 734. The plate holds end stops 736and limit switches to help protect against over-rotation of the servo732. The plate 738 is mounted to stand assembly 750 which holds theservo 732 so that the grabber assembly 730 is above conveyor 25.

Grabber assembly 730 includes a grabber mount 752, which is mounted tostrain relief 742, and which holds pneumatically-controllable verticalactuator 754 (part no. MXS16-30-AT-A93L available from SMC). Actuator754 is in fluid communication with vacuum ports 756 and is mounted tovertical plate 758, which in turn is connected to assembly arm 760. Thearm includes two fixed grabber arbors 764 that project downward. On thehidden underside of arm 760 are two annular chambers in which i.d. rings766 are compression fit. The i.d. rings are identical to i.d. rings 426,described above, in relation to FIGS. 4H-I. The annular chambers areeach in fluid communication via a vacuum gland (not shown) in arm 760which is in communication with vacuum ports 762. A plate 768 is attachedto arm 760 in the position corresponding to a bottom substrate. Plate768 is preferably made of UHMW plastic shaped to have a slightly raised,downward-projecting lip (not shown) of about 0.03 inches at an outerdiameter region. The lip provides support to a top surface of a bottomsubstrate so that a bottom station 508 may later vacuum grab an outerdiameter region of the substrate, as will be explained below. A sheath744 protects plumbing (not shown) from friction. Electrical strainrelief 746 is used to hold wiring and cap 748 covers the components.

The structure of a fixed arbor 764 of grabber assembly 730 is shown inFIGS. 7D-E in perspective and cross-section views. The arbor 764 ispreferably made of hardened and polished tool steel that is electro-lessnickel plated. FIG. 7E particularly shows the production specificationsof a preferred arbor 764, and Table 5 shows the sizes of thosedimensions measured in inches.

                  TABLE 5                                                         ______________________________________                                               dimension     size                                                     ______________________________________                                               A             0.687                                                           B             0.250                                                           C             0.311                                                           D             0.576                                                           E             0.410                                                           F             0.474                                                           G             0.5925                                                          H             0.08                                                            I             0.26                                                            J             .03 × 45°                                   ______________________________________                                    

An angled edge 766 of a downward projecting portion 768 of the arborfacilitates the handling of the substrates to place them on or off thearbor 764. The arbor 764 is shaped to fit into the i.d. hole of asubstrate and to engage the conveyor arbor 302 (see FIG. 3E) to depressarbor 302 into nest 304. Arbor hole 770 receives mounting hardware (notshown). The combination of arbors 302 and 764 forms a concentricityconstraint that keeps the top and bottom substrates of a combination 7aligned at the i.d. hole when the robot 502 transfers combinations 7 toconveyor 25. More specifically, the 15.0 mm center hole is maintained towithin +0.1 mm and -0.0 mm.

d. Top Station

The structure of a top station 510 of a dispense machine is shown inFIG. 5B and FIGS. 8A-B. FIG. 5B is an elevation view of a dispensemachine and illustrates that the top station 510 includes a stand 570 onwhich is mounted a plate 572 which is in horizontal alignment withbottom station 508. FIG. 8A shows the plate 572 in perspective view, andFIG. 8B shows the plate 572 in cross-section view and particularly showsthe production dimensions of a preferred plate 572. The sizes of thedimensions measured in inches are shown in Table 6.

                  TABLE 6                                                         ______________________________________                                               dimension     size                                                     ______________________________________                                               A             4.725                                                           B             4.675                                                           C             1.25                                                            D             0.724                                                           E             0.64                                                            F             45°                                                      G             45°                                                      H             0.03                                                            I             0.625                                                           J             R.25                                                            K             30°                                                      L             0.886                                                           M             2.5                                                             N             0.183                                                           O             1.0                                                             P             .03 × 45°                                   ______________________________________                                    

The stand 570 holds the plate in horizontal alignment with a top surfaceof bottom station 508. Preferably the plate 572 is made of UHMW plastic.Plate 572 includes a hole 876 sufficiently sized to receive the arbor764 of the grabber assembly 730. It also includes an upwardly-projectinglip 874 in alignment with upper surface portion 878. Lip 874 providessupport to a bottom surface (in this instance the moat-side, andmetal-side, if any) of the top substrate so that a top substrate bowdevice 512 may vacuum grab an outer diameter region of the substrate, aswill be explained below. Upper surface portion 878 provides support to abottom surface (in this instance the moat-side, and metal-side, if any)of the top substrate so that a top substrate bow device 512 may vacuumgrab a handling area region of the substrate, as will be explainedbelow. Holes 880 receive hardware (not shown) for mounting plate 572 tostand 570.

e. Bottom Station

The structure of a bottom station 508 of a dispense machine is shown inFIG. 9A-K in perspective and exploded views, along with FIGS. 10A-Bwhich show a perspective and exploded view of a rotary union similar toone used by the bottom station. The bottom station 508 includes an i.d.region grabber assembly 902 and an o.d. region grabber assembly 904 inoutward radial relation to assembly 902. The i.d. region grabberassembly 902 and the o.d. region grabber assembly 904 may be caused tovacuum grab a bottom substrate presented to it by robot grabber assembly730 of robot 502. The i.d. region grabber assembly 902 vacuum grabs asubstrate at a handling area region of a bottom surface of a bottomsubstrate, and the o.d. region grabber assembly 904 vacuum grabs asubstrate at an outer diameter region of a bottom surface of a bottomsubstrate. The vacuum grabbing elements, described below, are activatedwhen the vacuum grabber assembly 730 of robot 502 is in a state thatplaces plate 768 over the bottom station 508. In this fashion, thedownward projecting lip of plate 768 provides support to the o.d. regionand facilitates the vacuum grabbing of the o.d. region by a compressibleo.d. vacuum ring 906 of 45 durometer. In a raised state, assembly 902and 904 are in horizontal alignment, and in a lowered state, activatedunder programmatic control, the o.d. region grabber assembly 904 may beactuated vertically in the direction of axis arrow 910 to bow the bottomsubstrate concave down.

More specifically, the i.d. region grabber assembly 902 includes an i.d.ring 908 that is compression fit into an annular chamber of i.d.centering device 916 and around which i.d. chuck 914 is mounted. Ring908 is identical to the i.d. ring 766 of robot 502 and ring 426 of robot400. The i.d. centering device 916 includes an opening 951 through whicharbor 764 of grabber assembly 730 may fit and includes a vacuum gland952 (see FIG. 9G) in fluid communication with the annular chamber 950holding ring 908 and with a vacuum supply at the top of rod-mount 918.Rod-mount 918 is attached to servo 920 passes through plate 922 andabuts plate 924, which has holes in fluid communication with hub portsat a top surface of rotary union 926. Rotary union 926 receives vacuumat its sleeve ports (see FIGS. 10A-B) and provides the vacuum at hubports at the top surface. Thus, vacuum applied to rotary union 926 is influid communication with i.d. ring 908. Rod-mount 918 is attached torotary servo 920 (part no. DM1004C available from Compumotor) so thatthe i.d. region assembly may be caused to rotate under programmaticcontrol. (The above arrangement is the one used for 34 mm geometries.For 22 mm geometries the i.d. ring 908 is removed and replaced with astepped metal insert 970 (see FIG. 9H)).

The o.d. region grabber assembly 904 includes o.d. ring 906 that iscompression fit into annular chamber 932 of o.d. chuck 928. The annularchamber is in fluid communication with a vacuum gland (not shown) ando.d. vacuum port (not shown) on chuck 928. Thus vacuum applied to theo.d. vacuum port is in fluid communication with o.d. ring 906. The o.d.chuck 928 include recess 929 into which i.d. centering device 916 fitswhen the bottom station is in the raised state. The o.d. chuck 928 ismounted to plate 934 which in turn is mounted topneumatically-controllable bow actuator 936 (part no. Q97-4098 availablefrom Compact Air) which is mounted to the plate portion 919 of rod-mount918. Actuator 936 includes a fixed inner portion 939 and a movable outerportion 939 that is attached to plate 934 and thus may be used to causethe o.d. chuck 928 to move along the longitudinal direction of rod-mount918. Because the o.d. assembly is also attached to servo 920 viarod-mount 918 it moves in unison with the inner assembly 902.

The bottom station 508 further includes mounting hardware 942 to alignthe components as described above, a sheath 596 to cover the components,and a drain bowl 938 to catch resin residue, if any, from a dispensingoperation.

The structure of i.d. chuck 914 is shown in FIGS. 9D-E in perspectiveand cross-section views. A preferred chuck is made of UHMW plastic andis sized to fit around a projected portion 948 on top of a horizontalportion 949 of centering device 950. FIG. 9E shows the productiondimensions of a preferred chuck and table 7 shows the sizes of thesedimensions measured in inches.

                  TABLE 7                                                         ______________________________________                                               dimension     size                                                     ______________________________________                                               A              2.0                                                            B             1.522                                                           C             1.207                                                           D             1.118                                                           E             0.03                                                            F             0.25                                                            G             .07 × 45°                                          H             .05 RAD.                                                 ______________________________________                                    

The structure of i.d. centering device 916 is shown in FIGS. 9F-G inperspective and cross-section views. FIG. 9G shows the productiondimensions and table 8 shows the sizes of those dimensions measured ininches.

                  TABLE 8                                                         ______________________________________                                               dimension     size                                                     ______________________________________                                               A             0.995                                                           B             0.935                                                           C             0.815                                                           D             0.752                                                           E             0.595                                                           F             0.35                                                            G             .01 × 45°                                          H             0.060                                                           I             0.25                                                            J             0.22                                                            K             0.28                                                            L             0.348                                                           M             .01 RAD.                                                        N             0.213                                                           O             0.939                                                           P             0.2                                                      ______________________________________                                    

The centering device includes annular chamber 950 in to which ring 908is compression fit. Chamber 950 is in fluid communication with gland952. Opening 951 is sized to receive arbor 764 (see FIG. 7D).

The structure of stepped metal insert 970 is shown in FIGS. 9 H-I inplan and cross-section views. The metal insert is shaped to fit into theannular chamber used to hold the i.d. ring for the 34 mm geometryarrangement. It includes an initial elevation 762 of approximately 0.062inches and a total height 764. For the top bow device insert this heightis 0.172 inches and for the bottom station this is 0.162 inches. Theouter diameter 766 is approximately 0.998 inches and the inner diameter768 is about 0.752 inches.

The structure of o.d. ring 906 is shown in FIGS. 9 J-K in perspectiveand cross-section views. Ring 906 preferably has a durometer rating of45. The ring 906 is defined by angled lip 960, projecting up andradially outward, and angled lip 962, projecting up and radially inward.An annular region 964 is defined in-between and at a base of the lips.Thirty-six equally-distributed holes 966 of about 0.08 inch diameterextend through region 964. FIG. 9K particularly shows the productiondimensions of a preferred ring, and the sizes of the dimensions areshown in Table 9 measured in inches.

                  TABLE 9                                                         ______________________________________                                                dimension      size                                                   ______________________________________                                                A              4.53                                                           B              4.43                                                           C              4.333                                                          D              4.167                                                          E              4.07                                                           F              3.97                                                           G              0.55                                                           H              0.25                                                           I              0.136                                                          J              4.09                                                           K              4.41                                                   ______________________________________                                    

The structure of an exemplary rotary union 1000 is shown in FIGS. 10A-Bin perspective, exploded, and cross-section views. Rotary union 926 isidentical to the union 1000 shown except that the hub of union 926 issized differently to mate with plate 924 than the hub 1018 of union1000. Specifically the hub of union 926 is 3 inches in diameter and 0.5inches thick. Union 1000 includes a sleeve 1001, which receives body1002 over which o-rings 1003 are placed at o-ring grooves 1024. At eachend of sleeve 1001 and around body 1002 a bearing 1030 is placed, andoptionally a washer 1032. Snap ring 1034 facilitates holding theassembly together.

In operation sleeve 1001 is stationary and body 1002 may rotate aboutthe longitudinal axis of body 1002. A given port of sleeve ports 1006 isin fluid communication with a hub port pair 1014 of hub 1018. Thus, therotary union 1000 allows the provision of fluid, such as air underpressure or vacuum, to rotating hub 1018. Depending on the application,the fluid may emerge from a port on side 1016 of hub 1018 (as shown) orthrough a port 1019 on top surface 1020 (in this case shown plugged).

Sleeve 1001 has an outer diameter of about 1.75 inches and an inner boreof about 0.874 inches. Four sleeve ports 1006 extend through a surfaceof the sleeve 1001 and are positioned to be in alignment, when the unionis constructed, with port grooves 1008 of body 1002. Stepped opening1005 includes an outer opening of about 1.125 inches diameter and about0.126 inches deep to receive a top bearing 1030 and an inner opening ofabout 1.042 inches diameter and about 0.04 inches deep to form a gap toaccommodate an inner race bearing 1030. Identical openings exist at theopposite hidden end.

The body 1002 has an outer diameter at groove portion 1038 of about0.870 inches and a series of port grooves 1008 and o-ring grooves 10024.Each port groove 1008 has a corresponding o-ring groove on either side.Each groove has a depth of about 0.180 inches. The o-ring grooves 1024are machined at the inner diameter to have a curved surface, concaveradially outward. Each port groove 1008 has an opening 1010 (twoopenings being hidden from view) that extends radially inward and thatis in fluid communication with a gland (not shown) about 0.166 inches indiameter that extends to hub 1018. The hub 1018 includes four port pairs1014, each consisting of a hub port on a side edge 1016 of hub 1018 anda hub port on a top surface 1020 of hub 1018. Two neighboring o-ringgrooves are separated by a groove wall 1026 of about 0.108 inches wide,and groove walls 1028 are about 0.07 inches wide and separate an o-ringgroove 1024 and a vacuum port groove 1008. The o-ring grooves 1024 areabout 0.111 inches wide, and the port grooves 1008 are about 0.12 incheswide. The hidden surface of hub 1018 extends to a neck 1036 that isabout 0.146 inches deep and that has the same outer diameter of grooveportion 1038. Neck 1036 includes a stepped portion (not shown) about0.970 inches in diameter and about 0.02 inches deep immediately adjacentto hub 1018. Preferably the o-rings 1003 are well lubricated beforefitting them into o-ring grooves 1024. Snap ring groove 1036 is shapedto receive a snap ring 1034.

f. Top Substrate Bow Device

FIGS. 11A-E show top substrate bow device 512 in perspective andexploded views. Top substrate bow device 512 includes frame 1102 havingvertical supports 1104 and 1106 and horizontal member 1108. A horizontalactuator 1110 is carried over horizontal member 1108, and underpneumatic control it may be moved from a first position, which is invertical alignment with top station 510, to a second position, which isin vertical alignment with bottom station 508. The horizontal actuator1110 is connected to a vertical actuator 1112 which has substrate bowingassembly 1114 mounted to it. The vertical actuator 1112 is used to raiseand lower the bowing assembly 1114 to grab a substrate from the topstation 510 when in the first position and to lower the assembly 1312 toclose proximity of the bottom substrate on the bottom station 508 whenin the second position. The bowing assembly 1114 grabs and bows the topsubstrate as outlined above when describing the dispense operation.

More specifically, the bow assembly 1114 includes a rotary union 1116identical to the union 1000 described in relation to FIG. 10, coupled toa mount 1118 on one end and attached to actuators 1110 and 1112. Themount 1118 is coupled to spacer 1120, which limits the throw of bowactuator 1122 (part no. CQ2KWB25-10D-XG10 available from SMC). Actuator1122 is attached to housing 1124, which on its hidden surface includesfeatures for receiving compliance spring 1126, housing 1128, and o.d.ring 1134. Actuator 1122, under programmatic control, may be caused tolift the housing 1124 and thus the outer diameter region of the topsubstrate. Housing 1124 includes an annular chamber (not shown) on itshidden side into which o.d. ring 1134 is compression fit and which is influid communication with a vacuum gland (not shown). Vacuum is suppliedto the chamber via port 1125. Spring 1126 is preferably made of musicwire and has a diameter of 0.975 inches, a length of 0.88 inches, and awire diameter of 0.074 inches. Spring 1126 helps dampen the release ofthe housing 1124. The dampened release has been found to minimize theexistence of bubbles in eventually cured DVDs. The i.d. housing 1128receives vacuum through opening 1129, which is supplied by rotary union1116, via actuator shaft 1123. The i.d. housing 1128 includes featureson its underside to receive chuck 1130, i.d. ring 1132 and arbor 1136.The i.d. ring 1132 is compression fit into an annular chamber (notshown) that is in fluid communication with vacuum supplied by port 1129.The i.d. ring is identical to those described above. The chuck 1130 isidentical to chuck 914 described above (see FIGS. 9D-E). (The abovearrangement is the one used for 34 mm geometries. For 22 mm geometriesthe i.d. ring 1132 is removed and replaced with a stepped metal insert970 (see FIG. 9H)).

The structure of arbor 1136 is shown in FIGS. 11C-D in perspective andcross-section views. The arbor 1136 is preferably made of hardened andpolished tool steel that is electro-less nickel plated. FIG. 11Dparticularly shows the production dimensions of a preferred arbor 1136,and Table 10 shows those dimensions measured in inches.

                  TABLE 10                                                        ______________________________________                                               dimension     size                                                     ______________________________________                                               A             0.687                                                           B             0.250                                                           C             0.311                                                           D             0.576                                                           E             .15 RAD.                                                        F             0.410                                                           G             0.474                                                           H             0.5925                                                          I             0.131                                                           J             .03 × 45°                                          K             0.26                                                     ______________________________________                                    

Rounded edge 1138 facilitates mating with the i.d. centering device andhelps form a concentricity constraint to keep the i.d. holes of thesubstrates aligned. Hole 1140 receives mounting hardware (not shown).

After the top substrate is moved into vertical alignment with the bottomsubstrate and lowered, the top substrate is bowed 1.5-4 mm up at theouter diameter and the bottom substrate is bowed 0-2 mm down at theouter diameter.

g. Resin Dispenser

The structure of the resin dispenser 514 is shown in FIGS. 12A-C inperspective and exploded views. Resin dispenser 514 includes a stand1202 to hold mount 1220 which holds servo 1210 and waste cup 1214. Servo1210 (part no. DSRL-25-180-FW available from Festo) is connected tomounting plate 1222 to which is mounted horizontal actuator 1204 (partno. MXS12-50AS-A93L available from SMC). (Servo 1210 may be made torotate the dispense assembly 1212 counter-clockwise such that needle1215 is in vertical alignment with waste cup 1214, for example, duringmaintenance operations.) Actuator 1204 may be pneumatically controlled,by application of vacuum to vacuum ports 1216 and 1218, to move alongthe direction of arrow 1203 and is used to move needle 1215 into adesired position to dispense resin. Actuator 1204 holds micrometer plate1224 and micrometer controls 1206 and 1208 (part nos. 101-X-M-PL and101-X-M-PL-LEFT LOCK available from DEL-TRON). Micrometer controls 1206and 1208 are used to fine tune the orientation of needle 1215,respectively, horizontally or vertically to a desired position so thatthe dispensed resin may attain a desired trajectory as explained below.Holder 1226 is mounted to the combination of plate 1224 and controls1206 and 1208 and holds a pilot-actuated metering dispense valve 1228(part no. 752VW/SSHEAD available from EFD). Valve 1228 holds a needlecollar 1230 (part no. P-340 available from Upchurch Scientific.) andneedle 1215 and receives heated, pressurized resin through valve 1232.

The structure of needle 1215 is shown in FIGS. 12C-D. For 34 mm moatgeometries, needle 1215 is about 0.75 inches long and has a distal end1230, defined by a projection 1232 that is about 0.04 inches long, is 18gauge stainless steel and that has an inner diameter of about 0.0315 to0.0345 inches. Projection 1232 is adjacent to transition portion 1234which is defined by about a 10° radially outward extension until itreaches proximal portion 1236. Proximal portion 1236 has an innerdiameter of about 0.053 inches and is 15 gauge stainless steel. Needle1215 includes luer lock hub 1238.

For 22 mm moat geometries, the same needle 1215 is used but with thefollowing sizes. Needle 1215 is about 1.5 inches long and has a distalend 1230, defined by a projection 1232 that is about 0.04 inches long,is 18 gauge stainless steel and that has an inner diameter of about 0.03to 0.036 inches. Projection 1232 is adjacent to transition portion 1234which is defined by about a 10° radially outward extension until itreaches proximal portion 1236. Proximal portion 1236 has an innerdiameter of about 0.053 inches and is 15 gauge stainless steel. Needle1215 includes luer lock hub 1238.

The resin dispenser 514 is controlled to move resin needle 1215 into adesired position. Preferred embodiments have the dispense processparameters adjusted based on the moat geometries. The followingparameters are believed to be desirable starting points, but it isexpected that end users may desire to adjust these parameters.

For 34 mm geometries this position is such that the tip of the needle ispointed radially toward the center point of the DVD and disposed about19 mm from the outer diameter of the disk. The needle is approximatelyhorizontal with a centerline of the bowed substrates. The needle 1215projects resin about 5 mm while the bottom substrate is rotated atapproximately 30-40 rpm for about 1 revolution (350-370°). The resinviscosity is about 600 cps. At an inner diameter region the substratesare clamped with about a 2 inch diameter with about 0.1 inches roundedinterface edge due to the insert chuck.

For 22 mm geometries the resin is dispensed tangentially rather thanradially. The needle is positioned along a tangent to a radius of thedisk between 25-35 mm from the outer diameter. The needle may also bedeflected relative to this tangent according to an angle ⊖_(D) between0-30°. The needle is approximately horizontal with a centerline of thebowed substrates. The needle 1215 projects resin while the bottomsubstrate is rotated at approximately 40-50 rpm for about 1 revolution(355-365°). The resin viscosity is about 400 cps. At an inner diameterregion the substrates are clamped with about a 2 inch diameter withabout 0.1 inches rounded interface edge due to the insert chuck. Themetal insert (which replaces the i.d. rings for the top bow device andthe bottom station) provides approximately a 0.03 inch gap at the 2 inchdiameter interface.

The top substrate rotates in unison as a result of friction forces. Theresin is heated to approximately 70-90° F. and about 1-3 ml of resin isdispensed at approximately 20-30 psi (though the psi is viscositydependent). The above causes the resin to have a desirable arcuatetrajectory that just touches the concave up bow of the top substrate.The rotation of the substrates causes the dispensed resin to form acapillary bridge ring in-between the substrates; for the 34 mm geometrythis bridge is at approximately 20 mm-24 mm in from the outer diameter;for 22 mm geometries this bridge is at approximately 25 mm-35 mm. Theneedle 1215 is then retracted outwardly to clear the outer diameter ofthe substrates.

The bottom station and the top station then both begin to un-bow. Theun-bow rate is a function of the exhaust settings on the actuators andthe bottom station is set to un-bow at a slightly faster rate than thetop station. Near the end of the un-bowing of the bottom station thevacuum to the o.d. ring of the bottom station is released. Slightlylater the o.d. vacuum of the top bow device is released. The bottomstation is then actuated again to release the o.d. vacuum grip. The useof the compliance spring in the top bow device makes the un-bowing ofthe top station more consistent, effectively acting as a low passfilter.

Though a dispense machine 514 may operate with many types of resins,system 5 (see FIG. 2) preferably operates with resin L539-064 (400c.p.s) available from Quretech. The above arrangement has been found toform suitable capillary bridges on the substrates while achieving asuitably high fluid dispense velocity to minimize needle contamination,yet low enough to avoid fluid turbulence during dispense.

7. Spin Station

A preferred spin station 40 (see FIG. 2) includes spin station robot1302 (see FIGS. 13A-B) and two identical spin assemblies 1304 (see FIG.2 for plan view and FIG. 14A for perspective view). The spin assemblies1304 and robot 1302 are mounted on stands (not shown for robot) to placethem in alignment with the conveyor 25 (see FIG. 2), as described below.More specifically, robot 1302 is centered between index position 41 anda cure index position 46 in one direction, and between the two spinassemblies 1304 in an orthogonal direction (see FIG. 2).

The spin station 40 is responsible for receiving combinations 7 at index41 and producing spun combinations in which a fluid-state cure agent ismore evenly distributed in-between the substrates 6 of a combination 7,extending from an inward location at or very near the moats to the outerdiameter of the DVD.

a. Operation

The preferred spin station 40 is spaced from the dispense station 35 toallow a suitable time delay for capillary forces to attract the resin tothe facing moats of combination 7 (see FIG. 1B). Under a preferredembodiment, there is approximately a 24-28 second delay from thedispense station to the spin station for DVD5 and DVD10, and anapproximate 33-39 second delay for DVD9. This is accomplished with a 4.8second double-index cycle time for DVD5, a 5.2 for DVD9, and a 6.2 forDVD10. Because of the event-based control, the actual times experiencesome jitter.

Robot 1302 is positioned so that robot position 1360 corresponds toconveyor index 41, robot position 1362 corresponds to a first spinassembly 1304, robot position 1364 corresponds to cure index position46, and robot position 1366 corresponds to a second spin assembly 1304.

In a first state, the robot 1302 simultaneously vacuum grabs acombination 7 from conveyor position 1360 with arm 1306 and a spuncombination from a first spin assembly position 1362 with arm 1310. In asecond state, the robot 1302 rotates 90° clockwise about axis 1322 tosimultaneously transfer the combination from the conveyor position 1360to the first spin assembly position 1362 and the spun combination fromfirst spin assembly position 1362 to the cure position 1364. Thistransition to the second state correspondingly moves robot arm 1308 toconveyor position 1360 and arm 1312 to the second spin assembly position1366. While in the second state, the arm 1306 releases a combination tofirst spin assembly position 1362 and arm 1310 releases a spuncombination to cure position 1364. At the same time, arm 1308 grabs acombination from conveyor position 1360, and arm 1312 grabs a spuncombination from second assembly position 1366. In a third state, therobot 1302 rotates 90° counter-clockwise about axis 1322 tosimultaneously transfer the combination from the conveyor position 1360to the second spin assembly position 1366 and the spun combination fromthe second spin assembly position 1366 to the cure index position 1364.All of the above occurs under programmatic control and is repeated tointerleave the operation of two spin assemblies.

Each spin assembly 1304 vacuum grabs the combinations from below by aspin device 1402. For 34 mm moat geometries, a spin arm 1316 moves intoposition above the combination to form a vacuum seal above the topsurface of the top substrate and to create a vacuum in an interiorchamber 1320 of the combination (see FIG. 14E). (The use of spin arm1316 is optional for 22 mm geometries.) This vacuum created in theinterior chamber is used to hold the resin that has migrated to or verynear the moats. The spin device 1402 then spins the combinationaccording to a predetermined spin profile to cause the resin todistribute radially outward and evenly. The vacuum at the interiorchamber is chosen to balance the centrifugal forces created from thespin operation. Once spun, the combination is ready to be transferred byrobot 1302 to the cure station 45 (index 46 in FIG. 2; robot position1364 in FIG. 13A).

b. Spin Robot

The structure of spin robot 1302 is shown in FIGS. 13A-B in perspectiveand exploded views. The robot 1302 has four equal-length andequally-spaced arms 1306, 1308, 1310, and 1312, projecting radiallyoutward from axis 1322. The arms and upper assembly 1328 may be causedto rotate by rotary servo 1314 (part no: DR5030 available fromCompumotor) under programmatic control into one of the three statesdescribed above. Each arm has a downward projecting piston 1326 (partno: CDQ2WB15-50DCM-A731 available from SMC), which may be actuatedvertically under programmatic control as described above. At a distalend of each piston a pick head 1324 is attached.

Each pick head 1324 includes a housing 1330, having an annular chamber(hidden on underside) that is in fluid communication with a vacuum gland(not shown) that is in fluid communication with port 1342 connected tovacuum supply line 1328. An i.d. ring 1332 identical to those describedabove is compression fit into the annular chamber. A compliance spring1336 fits into a recess 1344 on the piston-side of housing 1330 and isheld at the other end by retainer 1338 and nut 1340 which threads on toa piston bolt. Spring 1336 is preferably stainless steel, has a diameterof 0.845 inches, a length of 1.5 inches, and a wire diameter of 0.055inches. A break-away post 1334 fits into an interior chamber 1346 ofhousing 1330 and screws onto a piston bolt (not shown) to hold the head1324 on to the piston 1326. Tapered features on 1334 and matchinginterior features of 1330 allow lateral/angular compliance when theassembly is caused to over-travel slightly.

c. Spin Assembly

The structure of spin assembly 1304 is shown in FIGS. 14A-D inperspective and exploded views. Spin assembly 1304 includes stand 1400on a top surface of which is mounted spin arm 1316 and underneath thetop surface of which is mounted spin device 1402. Robot 1302 transferscombinations through opening 1404 onto a top surface of spin chuck 1406.The top surface of spin chuck 1406 is in horizontal alignment withconveyor 25.

The structure of the spin device 1402 is shown more particularly in FIG.14B. Chuck 1406 is made of aluminum and includes an annular chamber influid communication with a vacuum gland (not shown). The vacuum gland,in turn, is in fluid communication with a vacuum port at the center ofthe chuck 1406 and that is coupled to spindle port 1410 of rotary vacuumsupply 1408 which supplies vacuum provided at input 1412. Thus vacuumapplied at input 1412 is in fluid communication with the annular chamberof chuck 1406. An i.d. ring 1414, identical to the ones described aboveexcept that its durometer rating is 55, is compression fit into theannular chamber and is used to vacuum grab the bottom surface of acombination at the handling area.

The structure of the metal spin chuck 1406 is shown more particularly inFIG. 14E. The i.d. arbor 1462 has an outer diameter of 0.591 inches +0.0and -0.001 inches. The curved portion 1462 has a radius of curvature ofabout R.3745. Analogously to cure chuck arbor 1530 (see FIG. 15D), arbor1320 includes three symmetric recesses of about R.25 radius to lessenthe surface contact with the i.d. hole of the combination. The chuckincludes a raised lip 1464 which starts at about 4.625 inch diameter andends at about 4.7 inch diameter and has a height of about 0.03 inches.

The rotary vacuum supply 1408 includes a housing and also have a bearingand is mounted to rotary servo 1416 (part no. MO-80 available fromMavilor) via adapter plate 1418. The rotary may be programmaticallycontrolled to implement a preferred spin profile. A preferred embodimentuses a dual acceleration profile that includes an initial accelerationof 50 rpss until a velocity of 1000 rpm±200 rpm is attained. Then thecombination is spun at that velocity for about 8 seconds ±2 seconds andthe combination is again spun at an acceleration of about 200 rpss untila velocity of about 2800 rpm±100 rpm is attained. The combination isspun at that velocity for about 0.5 to 1.0 seconds and then thecombination is decelerated at a rate of about 200 rpss until thecombination is caused to come to a rest. The dual acceleration profilecauses a relatively even distribution of resin to result free ofbubbles. It has been observed that the preferred spin profile whenoperating with the above preferred aspects and for 22 mm geometriescauses a substantially even bond layer of approximately 45-58microns±7-8 microns within a disk, and ±≦3 microns within any radius.

The chuck 1406 is contained within spin bowl 1416 which is shaped tocatch and drain to a reservoir (not shown) any resin projected as aresult of the spinning operation. An o-ring 1417 is positioned betweenthe chuck 1406 and the spin bowl 1416 to provide a seal. Another o-ring1418 is provided on a top surface of the spin bowl 1416 to provide aseal with the exhaust manifold 1420 mounted on top of o-ring 1418.Manifold 1420 catches and drains resin mist that may result from thespinning process, and a shield 1422 protects the combination from anyprojected resin or resin mist that moved upward and this protection maybe supplemented with splash back screens, for example, of medium mesh.

The structure of spinner arm 1316 is shown more particularly with FIGS.14C-E. Arm 1316 include a mount assembly 1430 which is connected to arotary (not shown) to rotate an extension 1432 about axis 1434 underprogrammatic control to position spin head 1436 over opening 1404 ofspin assembly 1304. The spin head 1436 includes a 0.094 inch diametervacuum gland (not shown) providing fluid communication to vacuum supply1438 and a downward-facing center port (not shown) in head 1436.

The head assembly's 1436 downward-facing port is aligned with an opening1449 of ring housing 1448, and is sealed by rotary seal 1456. Ringhousing 1448 is compression fit into a bearing 1454 which in turn iscompression fit into a recess (not shown) of head assembly 1436. Housing1448 includes a vacuum gland (not shown) that extends from opening 1449to a downward-facing port in the center of the housing. It also includesa downward-facing annular chamber (not shown) into which an i.d. ring1452, identical to those discussed above, is compression fit. The i.d.ring, in this instance, however, is not supplied with vacuum to vacuumgrab a substrate or combination; instead, it is used just to form a sealwhen the head 1436 is actuated downward to engage a top surface of acombination. Vacuum supplied by port 1438 is used to create the vacuumin the interior chamber 1420 of the combination. For 34 mm geometries,about 18-24 inches of mercury of vacuum are provided.

The assembly 1430 includes a mount 1431 to attach to the rotary servo(not shown) that rotates extension 1432 into position. Vertical actuator1440 (part no. MXU6-25-A93L available from SMC) is mounted to mount 1431to raise and lower the spin arm 1316 in the direction of axis 1442 toengage and disengage a combination through opening 1404 in the spinassembly.

8. Cure Station

A preferred cure station 45 (see FIG. 2) includes a cure table assembly1500 (see FIG. 15A-H), a thermal management system having a pre-coolingdevice 1600 (see FIG. 16A-C) and post-cooling devices 1800 (see FIGS.18A-B), and a lamp assembly 1700 (see FIGS. 17A-C). The cure tableassembly 1500 is mounted on a stand (not shown) to place a cure tablesurface 1508 in horizontal alignment with conveyor 25 and spin station40 (see FIG. 2). The pre-cooling device 1600 is vertically aligned witha pre-cooling index 1512 and above surface 1508. The lamp assembly 1700is vertically aligned with a curing index 1514 and above surface 1508,and post-cooling devices 1800 are vertically aligned with post-coolindexes 1516, 1518, and 1520 and below surface 1508.

The cure station 45 is responsible for receiving spun combinations (notshown) at a receiving index (index 46 in FIG. 2; robot position 1360 inFIG. 13A and FIG. 15A) and producing a cured DVD ready to be tested byfinishing station 50 (see FIG. 2).

a. Operation

After a combination is spun by the spin station, the spin robot 1302transfers it to a free-floating cure chuck 1530 at receiving index 1360of cure table assembly 1360. Once there, the combination isdouble-stepped through the cure table 1502 to perform certainpre-cooling, curing, and post cooling operations.

More specifically, a spun combination makes the following path indicatedby the arrows through a nine-index, double-step cure table 1502. Thecombination is received at 1360 and double-stepped to cure index 1510.Though two cure indexes are stepped, this occurs in one index interval.

Next, the combination is double-stepped to pre-cool index 1512 where atop surface of the spun combination is pre-cooled. In short, thepre-cooling operation is intended to pre-shrunk the top surface as aninverse operation to the thermal expansion that will occur in asubsequent cure operation.

The combination is then double-stepped to curing index 1514 where thespun combination is raised by a cure chuck lifting assembly 1560 (seeFIGS. 15F-H) into a lamp assembly 1700 (see FIG. 17) and cured with UVlight. This curing operation will introduce energy that is absorbed inpart by the combination and by cure chuck 1530. Raising the chuck 1530to the lamp assembly helps isolate the energy absorption to the chuck1530, and helps insulate the table 1502, which facilitates thermalmanagement. During the curing operation, the cure chuck lifting assembly1560 vacuum holds the entire combination flat and rotates thecombination. This facilitates even curing and reduces warping.

The cured combination is then double-stepped in sequence throughpost-cooling indexes 1516, 1518, and 1520. At each post-cooling index apost cooling device 1800 (see FIG. 18) is raised into contact with thecure chuck 1530 to help cool the chuck.

The combination is then double-stepped to index 1522 where the cured,cooled combination (i.e., the DVD) is removed by the finishing station50.

Cure index 1524 is an empty station.

a. Cure Table Assembly

The structure of the cure table assembly 1500 is shown in FIGS. 15A-H inperspective and exploded views. The assembly 1500 includes a nine-indexaluminum cure table 1502, an aluminum cure chuck 1530, and a cure-chucklifting assembly 1560, positioned below cure index 1514. The table 502is double-step rotated, i.e., 40° at a time, counter-clockwise by aservo (not shown). The table 502 includes nine beveled openings 1526shaped to mate with a beveled surface 1532 of cure chuck 1530.

The structure of cure chuck 1530 is shown in FIGS. 15B-C in perspectiveand cross-section views. The chuck 1530 includes thirteen outer grooves1534 and two inner grooves 1536. Each of the grooves is in fluidcommunication with a vacuum gland 1538 that is in fluid communicationwith a vacuum port 1540. Each groove is about 0.040 inches wide. Theoutermost groove 1542 is about 0.3 inches from the chuck's edge. Theinnermost groove 1544 is about 0.383 inches from the centerline of thechuck 1530. Each groove is separated from a neighboring groove by about0.120 inches, except that the innermost outer groove 1546 is separatedfrom the outermost inner groove 1548 by about 0.337 inches. (Allseparations are measured centerline to centerline.) The productiondimensions of a preferred chuck 1530 are shown in FIG. 15C, and thesizes of those dimensions are shown in Table 11 measured in inches.

                  TABLE 11                                                        ______________________________________                                                dimension      size                                                   ______________________________________                                                A              0.34                                                           B              0.3                                                            C              90°                                                     D              0.312                                                          E              5.164                                                          F              0.35                                                           G              0.165                                                          H              0.09                                                           I              0.605                                                          J              60°                                                     K              0.196                                                          L              4.276                                                          M              4.940                                                          N              0.1                                                            O              60°                                             ______________________________________                                    

Projection 1550 is sized to receive a cure chuck arbor 1554 (see FIGS.15D-E) and recess 1552 is shaped to receive the cure chuck liftingassembly 1560 (see FIGS. 15F-H and the post-cooling devices 1800 (seeFIG. 18A).

The structure of cure chuck arbor 1554 is shown in FIGS. 15D-E inperspective and cross-section views. The arbor is preferably made ofhardened and polished tool steel that is electro-less nickel plated. Theshape of the arbor 1554 forms a concentricity constrain together withthe spring-loaded pick head 1324 (FIG. 13B) of the spin robot 1302. Thearbor includes five equally spaced projections 1556 defined by cutaways1157 having a radius of curvature of R.125. FIG. 15E shows theproduction dimensions of a preferred chuck arbor 1554, and the sizes ofthose dimensions are shown in Table 12 measured in inches. The recessedshape of arbor 1554 lessens the surface area of the arbor that couldpotentially become contaminated with resin.

                  TABLE 12                                                        ______________________________________                                               dimension     size                                                     ______________________________________                                               P             0.211                                                           Q             .083                                                            R             .052                                                            S             R.206                                                           T             0.173                                                           U             0.35 × 45°                                         V             0.1                                                             W             0.204                                                           X             0.313                                                    ______________________________________                                    

A two-piece cure pad 1525 (see FIG. 15F) having outer piece 1527 andinner piece 1526 is placed over each chuck 1554 to distribute the vacuumsupplied by port 1540 during the curing operation. A preferred pad 1525is made of 0.0375 inch U.V. rubber (durometer value of 65) with pressuresensitive adhesive. FIG. 15F shows the production dimensions of apreferred pad, and Table 13 shows the size of those dimensions measuredin inches (all measurements except Y and EE are radius measures).

                  TABLE 13                                                        ______________________________________                                                dimension      size                                                   ______________________________________                                                Y               5°                                                     Z              1.68                                                           AA             1.92                                                           BB             2.16                                                           CC             2.4                                                            DD             2.64                                                           EE             2.5°                                                    FF             2.88                                                           GG             3.12                                                           HH             3.36                                                           II             3.6                                                            JJ             3.84                                                           KK             4.08                                                           LL             4.34                                                           MM             4.56                                                           NN             1.01                                                           OO             0.593                                                          PP             0.77                                                           QQ             4.66                                                           RR             1.28                                                           SS             1.5                                                    ______________________________________                                    

Ring 1528, unlike all other rings of both pieces 1526 and 1527, has itsholes spaced 5° apart. All other rings, e.g., 1529, have their holesspaced 10° apart Each hole is 0.025 inch diameter. The distribution ofvacuum holes has been observed to effectively hold the combinationduring the curing process while minimizing dimpling and waffling effectswhile combatting warping forces and providing thermal stability.

The structure of cure chuck lifting assembly 1560 is shown in FIGS.15G-H in perspective and cross-section views. Lifting assembly 1560 ismounted below and in vertical alignment with index 1514 so that lifterhead 1566, under programmatic control, may be raised to engage recess1552 and vacuum grab chuck 1530 to both hold chuck 1530 and to providevacuum to port 1540 so that the chuck may hold the combination. Under apreferred embodiment, 850 mbar (max) of vacuum is applied to hold thechuck and the combination.

More specifically, head 1566 has a vacuum gland extending through itsshaft 1565 that is connected to a vacuum supply (not shown). A topsurface of head 1566 includes an annular chamber 1569 for holding anouter diameter o-ring 1570 and an annular chamber 1567 for holding aninner diameter o-ring 1568. The o-rings are used to help seal vacuumwithin recess 1552 of chuck 1530 and to assist with any deflection ofthe chuck resulting from the application of vacuum. The head 1566 isbolted to plate 1572 which is bolted to servo 1562 (part no.M-JS0002FN001 available from NSK). Servo 1562 is attached to mount 1574having vertical guides 1575 mounted within fixed mount 1576. The mount1574 may be raised or lowered within guides 1575, under programmaticcontrol, by cam 1565 and rotary actuator 1564 (part no.11912/DSR-32-180-P available from Festo).

c. Pre-Cooling Device

The structure of the pre-cooling device 1600 is shown in FIGS. 16A-D inperspective and exploded views. Pre-cooling device is mounted above andin vertical alignment with cure index 1512. The device 1600 is caused toblow turbulent cool air preferably at about 35-60° F. and at about 1-5cfm onto a combination one double-step before the combination issubjected to the curing process. The pre-cooling will cause a topsurface of the top substrate of a combination to have a lowertemperature than a bottom substrate and thus cause the combination toshrink accordingly from the shrinkage induced in the top substrate. Thisshrinkage is designed to roughly match the inverse of the warping thatresults from the curing process. In short, the curing process will causethe top substrate to heat and thus expand. Without more, the curing andsubsequent cooling would cause the combination to warp concave up. But,with the pre-cooling this effect is reduced by effectively pre-shrinkingthe combination, before the resin is cured.

Pre-cooling device 1600 includes a stand 1602 holding a vortex tube 1604(part no. 3440 available from ExAir) to generate cool air and cone 1606to distribute cool air. The cone 1606 and tube 1604 are connected bysupply hose 1605. The cone 1606 contains a baffle 1608 on its undersideto move flow distribution away from the center of the disk. Theproduction dimensions of a preferred cone 1606 and baffle 1608 are shownin FIGS. 16B-D, and the sizes of the dimensions are shown in table 14.

                  TABLE 14                                                        ______________________________________                                                dimension      size                                                   ______________________________________                                                 A             1.403                                                          B              1.0                                                            C              0.578                                                          D              1.5                                                            E              30°                                                     F              4.724                                                          G              0.128                                                          H              0.047                                                          I              0.094                                                          J              0.578                                                          K              0.25                                                           L              5.274                                                          M              0.578                                                  ______________________________________                                    

d. Lamp Assembly

The structure of the lamp assembly 1700 is shown in FIGS. 17A-B inperspective and cross-section views. The lamp assembly 1700 ispositioned above and in vertical alignment with cure index 1514 so thatthe lifting assembly 1560 may raise a vacuum-grabbed combination intothe assembly 1700.

The assembly 1700 includes a stand 1702 holding a nest 1703 having afirst angled surface 1716 for mounting a first UV lamp 1704 and a secondangled surface 1714 for mounting a second lamp 1706. A liquid-cooledtunnel 1708 is positioned above index 1514 and receives the combinationto be cured. To filter IR radiation caused by the lamps 1704 and 1706, afirst dichroic filter 1712 is positioned at an angle relative to lamp1704 and a second dichroic filter 1710 is positioned at an anglerelative to lamp 1706.

The cure lamps 1704 and 1706 are preferably F300 lamps available fromFusion, Inc. with `D` type bulbs. The bulbs from these lamps are normalto the Figure and emit a beam of light toward the combination, which isparallel to the top of tunnel 1708, toward the outer diameter of theinner mirror band of the combination. The first and second angledsurfaces 1716 and 1714 of nest 1703 hold the lamps 1704 and 1706 to havea target distance of 3.125 inches and an angle of incidence of 30°. Thelamps hold the bulbs approximately 2.1 inches from the face of the lampand have elliptical reflectors arranged around the bulbs.

Angle 1720 is preferably maximized provided that the above targetdistance and angle of incidence are substantially maintained. Withcurrently-available lamps 1704 and 1706, this angle is about 30°. Thefilters 1710 and 1712 are diachrilic cold reflectors and IR hotreflectors (part no. 526451 available from Fusion).

FIG. 17C shows the positioning of the lamps. FIG. 17D shows the lightpattern resulting from the superimposed beams, in particular thepercentage of light relative to the position on the substrate. As can beseen the light pattern is essentially flat across the entire area ofinterest. The angled light effectively directs the UV light at the sidesof the metallized pits. These metallized pits have been found to havemost of their reflective or semi-reflective material on the top of thepits and less material on the sides of the pits. Thus, by directing thelight at the desired angle a much larger portion of the emitted UV lightis transmitted through the metal into the space between the substrateswhere it can cure the resin and much less is reflected by thecombination's metallized surface. Thus, UV energy is more efficientlytransmitted to the bond resin resulting in less thermal stressing of thecombination Cooler combinations, in turn, reduce warping which otherwiseoccurs as a result of the thermal gradient between upper and lowersubstrates as described above. In contrast to conventional techniqueswhich emit UV light normal to the surface of the combination, thepreferred arrangement allows for lower intensity UV curing.

The tunnel 1708 is formed from cooper cylinder with coiled tubing silversoldered to it. The assembly is painted with black high temperatureenamel and carries water at approximately 10-15° C. The tunnel isapproximately 4 inches high and helps maintain a stable air temperaturewithin cure station.

During the cure operation the combination is rotated by lifting assembly1560 at an angular velocity of between 200-400 rpm.

The combination is subjected to the lamp energy for a predeterminedtime. Under a preferred embodiment that uses the Quretech resinidentified above, the combination is subjected to light for 2.5 secondsfor DVD5 disks, 3 seconds for DVD9 disks, and 3.5 seconds for DVD10.

The combination is raised and simultaneously rotated through tunnel 1708so that the UV light emitted from lamps 1704 and 1706 has an effect asif the combination was suddenly flooded with light, rather thangradually exposed to increasing intensity of light.

e. Post Cooling Device

The structure of the post cooling device 1800 is shown in FIG. 18 inperspective view. A post cooling device is positioned under indexes1516, 1518, and 1520 to help cool the cure chuck 1530 after it has beenheated as a result of the curing operation.

More specifically, post cooling device 1800 includes a liquid cooledchuck 1802 having a top plate 1804 mounted and sealed to a housing.Housing receives water at about 10-15° C. from supply lines 1810. Thehousing is mounted to vertical actuator 1812 (part no. CXSL15-10available from SMC) which is attached to mount 1822. Actuator 1812 underprogrammatic control may be caused to raised the chuck 1802 into contactwith recess 1552 of cure chuck 1530.

Post-cooling facilitates testing in that any scanning operations or thelike are performed on disks at approximately room temperature.

9. Other Embodiments

The above embodiment focused on a preferred low power curing system.Many of the combinations of processing parameters may yield desirableresults.

The above embodiment focused on one exemplary in-line system. The actualarrangement was influenced by the economics of various stations. Forexample, the metallizer and molding machines are the most expensivestations and thus the remainder of the construction was largelyinfluenced with a goal of keeping those stations busy. Thus higher orlower degrees of interleaving of other stations, e.g., dispense, areclearly within the ambit of the invention.

Moreover, there is a wide degree of flexibility and choice in thevarious handling mechanisms and robots, though certain aspects thereofare believed to be particularly novel, e.g., concentricity constraint.

In an exemplary embodiment, the top substrates of DVD5 format are notpresented to the metallizer. Under alternative embodiments, the topsubstrate is presented to the metallizer but the metallizer is notenergized to sputter that substrate.

One described embodiment pre-shrinks the top substrate in anticipationof its subsequent expansion during the curing operation. Alternatively,the bottom substrate could have been pre-expanded.

The described embodiments focused on a two lamp arrangement but theabove teachings also apply to other arrangements including those withmore or less lamps and different types of lamps.

Likewise, even for the two lamp arrangements various sub-arrangementsmay be desirable. As described above, the lamps may be arranged so thatthe superimposed pattern is desirable, though the pattern from a singleone of the lamps may be less than desirable. Besides the aboveembodiment, for example, arrangements in which the lamps have a targetdistance of 4.1 inches are believed to be desirable, among others.Likewise, variations in the angles may be desirable.

The process parameters may be adjusted by the user. These parametersinclude, but are not limited to, the amount of metallization, thepositioning of the metallization, the positioning of the resin needle,the angular velocity of the disks while resin is dispensed, the pressureand temperature of resin, the index interval, and the spin profile.Users may adjust these parameters to respond to observations made on themanufactured DVDs. For example, if the resin layer is thicker thandesired one approach would be to increase the angular velocity of thecombination during resin dispensing. Likewise the parameters may beadjusted based on process materials, such as the resin type used.

The preferred embodiment was described with reference to event-basedcontrol but other mechanisms could be substituted.

Certain conventions were carried throughout the description portion,e.g., top and bottom substrate, the meaning of "vacuum" etc. It shouldbe understood that those conventions were intended to aid clarity of thedetailed description and not to be definitions of those terms limitingthe scope of the following claims.

Having described an exemplary embodiment, it should be apparent topersons of ordinary skill in the art that changes may be made to theembodiment described without departing from the spirit and scope of theinvention.

What is claimed is:
 1. A method of curing a combination of a top and a bottom substrate with a resin disposed in-between, comprising:performing a single curing operation that inherently warps the combination in one direction and fully cures the resin; inducing a temperature gradient between the top and bottom substrate to manipulate the combination in a direction opposite to the one direction wherein the temperature gradient inducing operation is performed before the curing operation.
 2. The method of claim 1 wherein the temperature gradient inducing operation cools the one of the top and bottom substrates that the curing operation inherently heats more.
 3. The method of claim 2 wherein the substrate is forced convection cooled.
 4. The method of claim 3 wherein the convection cooling blows turbulent air having a temperature between about 35°-60° F. on to the one of the top and bottom substrates that the curing operation inherently heats more.
 5. A system for curing a combination of a top and a bottom substrate with a resin disposed in-between, comprising:a single cure device that inherently warps the combination in one direction and fully cures the resin as a result of a single curing operation that the cure device performs on the combination; a temperature gradient inducing device disposed closer to one of the top and bottom substrates to create a temperature gradient between the top and bottom substrate and thereby manipulate the combination in a direction opposite to the one direction wherein the temperature gradient inducing device is arranged to operate before the cure device is to operate so as to thermally manipulate the combination before curing.
 6. The system of claim 1 wherein the temperature gradient inducing device is disposed closer to the one of the top and bottom substrates that the cure device inherently heats more and wherein the temperature gradient inducing device includes a cooling assembly for cooling the top substrate.
 7. The system of claim 6 wherein the cooling assembly includes a convection cooling device.
 8. The system of claim 7 wherein the convection cooling device blows turbulent air having a temperature between about 35°-60° F. on to the one of the top and bottom substrates that the cure device inherently heats more. 